1. Technical Field
The present invention relates to a vertical-cavity surface-emitting laser diode (hereinafter referred to as VCSEL), a method for fabricating a VCSEL, and an optical transmission apparatus.
2. Related Art
In the fields of electronic storage apparatus or optical transmission, VCSELs have been used as light sources. A VCSEL may include, on a substrate, an upper and a lower semiconductor mirror layers sandwiching an active region; and emit a laser light beam perpendicularly with respect to the substrate. For a selective oxidation-type VCSEL, an oxidation controlled layer for performing current confining and light confining is formed in proximity to the active region to make the diameter of an oxidation aperture of the oxidation controlled layer smaller, thereby the VCSEL is operated in a single traverse mode. To obtain the single traverse mode, the diameter of the oxidation aperture should be as small as about three micrometers; therefore, for such a VCSEL, it has been desired to improve optical output and electrostatic discharge (ESD) resistance, and lower resistance value and heat dissipation, and extend lifetime, and increase productivity.